1. Field of the Invention
The present invention relates to a laser scanning device for projecting a laser beam against a target having information contained thereon which is to be scanned by the laser beam; and more particularly, relates to a compact laser scanning device which is a bar code reader and which incorporates internal unitary structure with an integral scanning motor for compactly supporting various laser and optics components for modular installation in the device, and which protects at least the integral scanning motor from external impacts and shock loads.
The utilization of laser scanning devices for the scanning or reading of information provided on a target; such as a package or sale item, is well known in the technology and in commerce. In this connection, various types of laser scanning devices incorporate scanning heads which house optical reading systems, such as bar code readers, for the reading of bar code symbols on targets which are scanned by a laser beam projected from the bar code reader. In general, such laser scanning devices; especially in the type of bar code readers, are widely employed in industry and in retail commerce and, for example, may be permanently incorporated in the structures of check-out counters of supermarkets, whereby the items of merchandise having the bar code symbols imprinted thereon or applied thereto are passed over a fixed bar code reader located beneath the counter surface so as to provide a record for the merchant of the merchandise being purchased by a consumer, and concurrently a readout (and possibly a printed record) for the consumer.
The bar code reader or laser scanning device may also be constituted of an optical scanner unit which is fixedly mounted on a stand extending above a support platform or countertop on which the merchandise may be arranged; or alternatively, in many instances of utilization, may be in the form of a miniature, lightweight and gun-shaped device having a pistol grip, wherein the device is normally passed over the bar code symbol which is imprinted on a sale item at some short distance therefrom so as to enable scanning of the information provided by the bar code symbols.
2. Discussion of the Prior Art
Hereby, laser scanning devices in the form of bar code readers are described in detail in U.S. Pat. No. 4,387,297, assigned to the same assignee of the present invention and incorporated by reference herein. Thus, the laser scanning system disclosed in the above-mentioned U.S. Pat. No. 4,387,297 includes a portable hand-held scanning head which may be of any suitable configuration, but preferably has a gun-shaped housing consisting of lightweight plastic, and with a handle and barrel portion of the housing enabled to receive the various components of the scanning head therein. Within the barrel portion there is generally mounted a light source, an optic train including focusing lenses for directing the light beam across a bar code symbol on the target, and sensing means for detecting reflected light from the bar code symbol which is being scanned.
Other structures for laser scanning devices in the form of bar code readers, in addition to the above-mentioned U.S. patent, are also described in more specific detail in U.S. Pat. Nos. 4,760,248; and 4,409,470, all of which are assigned to the same assignee as the present invention and incorporated by reference herein.
The structures of the foregoing patents, and referring particularly to the disclosures of assignee's U.S. Pat. Nos. 4,387,297 and 4,409,470, incorporate shock mountings for protecting the rather delicate operative components of the laser scanning devices from sustaining any damage or even from being entirely destroyed when the devices are subjected to hard impacts or shock loads, such as by being dropped or struck by a hard object.
Another hand-held gun-shaped laser scanning device of that type is disclosed in the Eastman, et al. U.S. Pat. No. 4,652,750. In that instance, a laser diode and optics for forming a scanning beam and a photodetector are mounted as a unitary or modular structure on a printed circuit board enabling the entire arrangement to be fixedly located in the housing of the laser scanning device.
All of the foregoing devices satisfactorily meet the demands of industry in the intended applications thereof, such as through the various configurations and embodiments imparted to the laser scanning devices, particularly such as bar code readers which are well-known in the technology and widely employed in commerce with a large degree of success and consumer acceptance, and which incorporate shock mountings and the like utilized in protecting the rather delicate internal operative components such as the laser generating, optical and scanning motor from damage when the scanning devices are subjected to hard externally-generated impacts or shock loads. Nevertheless, further improvements in protecting these components can be contemplated, for instance, when the laser scanning device is in the form of a hand-held bar code reader, a portable gun-shaped housing member consisting of lightweight plastic containing the operative components, and especially in avoiding any damage to the normally expensive scanning motor which may be contained in the housing member.